The present invention relates to forced air coolers and more particularly to coolers which are particularly adapted for use in schools as a milk cooler with easy access to students at the school.
There are various types of milk coolers and dispensers in commercial use at the present time. Some provide access to the interior for removal of small milk cartons by school children. However, these may be categorized as of two basic types, free convection and forced convection, with respect to the arrangements and methods for producing and maintaining refrigeration in the cabinets for the coolers. One of the basic types utilizes an evaporating unit of a refrigeration system at the side ends of the cabinet so that refrigerated air is circulated from one end of the cabinet to the other end. This forced convection arrangement is rather costly for the task involved and is inefficient with respect to circulating air since the flow of air from one end of the cabinet competes with the flow of refrigerated air from the other end. The resultant airflow is turbulent and lacks the uniformity necessary for predictable and usable refrigeration throughout the entire cooler cabinet.
In another forced air arrangement for refrigeration in a milk cooler, the evaporator is located below the floor of the cabinet, and it is driven upwardly across the top of the cabinet and downwardly in circulating fashion. In this arrangement, refrigerated air being driven upwardly competes with the normal gravitational downward flow of cold air. This arrangement does not produce a uniform stream of refrigerated air in a circulating path around the interior of the cooler cabinet.
In the free convection arrangement, the metallic tubing utilized for providing refrigerated air is in contact with a wall of the cooler cabinet which actually and directly produces the refrigerated air. This indirect transfer of a refrigerant to air to be circulated results in the lessening of the production of refrigerated air within the cabinet and sustaining the same. In order to overcome this disadvantage, steps must be taken to augment this loss by increasing the capabilities and ratings of the devices utilized in the refrigeration system for this particular type of cooler.